1. Field of the Invention
The present invention relates to a laser treatment apparatus for performing treatments on an affected part by irradiating the part with a treatment laser beam.
2. Description of Related Art
There have been conventionally known laser treatment apparatuses for performing treatments on a patient""s eye by irradiating a treatment laser beam to the eye. This type of the apparatuses would generate high heat from a laser oscillator, or a laser head. Accordingly, the laser head should be cooled by heat radiation. As a cooling mechanism therefor, there are a forced-air-cooled type and an internal circulation water-cooled type. In the internal circulation water-cooled type, cooling water (coolant) is circulated around the laser head to cool it. The cooling water having increased in temperature due to the heat absorption from the laser head radiates the heat through a radiator. An electric fan is driven to send a current of air to the radiator, so that the radiator is forced to radiate the heat.
In the conventional apparatuses of the forced-air-cooled type and the internal circulation water-cooled type, however, the driving speed of the electric fan is controlled so as to linearly change according to temperatures. This would cause a problem that the fan makes large noises even during regular use where the temperature of the fan is not raised so high.
In particular, the laser treatment apparatus is generally used in an operating room of ophthalmological clinics or hospitals. The apparatus therefore has to control noise caused therefrom in order to eliminate the anxiety of a patient or reduce a burden on an operator.
The present invention has been made in view of the above circumstances and has an object to overcome the above problems and to provide a laser treatment apparatus capable of reducing noises produced by a cooling fan to thereby improve a treatment environment.
Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the purpose of the invention, there is provided a laser treatment apparatus for performing treatments on an affected part by irradiating the affected part with a laser beam for treatment, the apparatus including: a laser oscillator: a cooling unit including a fan which cools the laser oscillator; a temperature sensor which directly or indirectly detects a temperature of the laser oscillator; and a control unit which drives the fan at roughly constant low speed when a detected temperature by the temperature sensor is below a predetermined reference value and at roughly constant high speed when the detected temperature is the predetermined reference value or more.
According to another aspect of the present invention, there is provided a laser treatment apparatus for performing treatments on an affected part by irradiating the affected part with a laser beam for treatment, the apparatus including: a laser oscillator; a cooling water circulation unit including a pipe and a pump which circulate cooling water through the laser oscillator; a radiator provided with a fan for making heat radiation of the cooling water; a water temperature sensor which detects a temperature of the cooling water drained from the laser oscillator after circulation therethrough; and a control unit which drives the fan at roughly constant low speed when a detected temperature by the water temperature sensor is below a predetermined reference value and at roughly constant high speed when the detected temperature is the predetermined reference value or more.